Using the classically conditioned rabbit nictitating membrane response (NMR) as a model system for studying mammalian learning, support is sought for investigations of the role of the hippocampal cholinergic system in acquisition of the conditioned NMR. The proposed studies involve microinjecting cholinergic agonists and antagonists into hippocampus and monitoring acquisition of the CR. In doing this we hope to not only further exploit the rabbit's conditioned NMR as a model system for associative learnng, but to also begin to assess the preparation's viability as an animal model of human memory disorders which appear related to the hippocampal cholinergic system.